exercise_8 - Molecular Dynamics Simulations 2011 Exercise 8...

Info iconThis preview shows pages 1–2. Sign up to view the full content.

View Full Document Right Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: Molecular Dynamics Simulations 2011 Exercise 8: Suggested solutions Eero Holmstr¨ om November 9, 2011 1. The standard deviation of the total energy per atom E (column 6 in the output of mdmorse ) for the set of 10 ps runs is presented in Table 1. The fluctuations are seen to be very small for cut-offs of 4.0, 6.0 and 8.0 ˚ A, but larger at 4.5 and 5.0 ˚ A. To explain this, let’s look at Fig. 1, where the pair correlation function is plotted against the Morse potential. We see immediately that with r c = 4 . 5 and 5.0 ˚ A, we are at a peak in the pair correlation function, namely at the third and fourth nearest neighbors, respectively. Now, as the atoms vibrate due to thermal motion, the third neighbor in the first case and the fourth neighbor in the second case gets cut off one moment and taken into account again the next moment. This causes fluctuation in the potential energy and hence the total energy of the system. As the peak in the correlation function and the strength of the potential are smaller at...
View Full Document

This note was uploaded on 02/14/2012 for the course CSE 6590 taught by Professor Kotakoski during the Winter '12 term at York University.

Page1 / 5

exercise_8 - Molecular Dynamics Simulations 2011 Exercise 8...

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online